Magnolol

Magnolol is a lignan found in the bark of magnolia trees, principally Magnolia officinalis, which has been used in traditional Chinese medicine for centuries. It appears in cosmetics as an isolated compound rather than as a bark extract.

Isolated compound versus extract

Worth noting, because it changes what the label tells you.

Most plant-derived ingredients appear as extracts. The INCI name gives you the plant and the part used, and nothing about extraction method or active concentration, which vary enormously between suppliers.

Magnolol is a single defined molecule with a known structure at a known purity. Two products containing magnolol can be compared meaningfully in a way that two products containing magnolia bark extract cannot.

How it works

Magnolol is a potent antioxidant, and research also reports anti-inflammatory activity through effects on inflammatory signalling pathways, including NF-κB.

It has documented antimicrobial activity, which is why magnolia extracts appear in oral care as well as skincare, and studies have examined effects on sebum and on the appearance of redness.

Magnolol and honokiol

Magnolia bark contains two closely related lignans, magnolol and honokiol. They are structural isomers, meaning the same atoms arranged differently, and their activity overlaps considerably.

Extracts contain both. An isolated ingredient will specify which, and magnolol is the more common in cosmetic formulation.

The evidence

The pharmacological literature on magnolol is substantial, spanning inflammation, neuroprotection and antimicrobial activity. Most of it is laboratory or animal research rather than topical human trials.

The antioxidant and anti-inflammatory mechanisms are well characterised. What that translates to in skin, applied topically at cosmetic concentrations, is less established.

Pregnancy

Magnolia bark has traditional medicinal uses and there is limited safety data for topical application during pregnancy. Worth confirming with your doctor.